250 results about "Brewster's angle" patented technology

In order to make a reflection coefficient in boundary surface between materials to be zero and permeate 100% of a light independent of a polarization direction, an optical device made of an optical material composed of a metamaterial prepared by arranging a plurality of at least either of electrical resonators or magnetic resonators each being smaller than a wavelength of a light wave in only a predetermined plane, and at least either of the electrical resonators and the magnetic resonators arranged functioning with respect to s-polarization, whereby at least either of the dielectric constant or the magnetic permeability is controlled in response to the function to induce a Brewster phenomenon in the s-polarization wherein the incident plane of a light wave being set out at a Brewster's angle with respect to the p-polarization and further at least either of the dielectric constant and the magnetic permeability of the optical material being controlled with respect to the s-polarization of the optical material, whereby the Brewster condition is independently satisfied in both the p-polarization and the s-polarization at the same time.

A method and apparatus for performing laser thermal processing (LTP) using a two-dimensional array of laser diodes to form a line image, which is scanned across a substrate. The apparatus includes a two-dimensional array of laser diodes, the radiation from which is collimated in one plane using a cylindrical lens array, and imaged onto the substrate as a line image using an anomorphic, telecentric optical imaging system. The apparatus also includes a scanning substrate stage for supporting a substrate to be LTP processed. The laser diode radiation beam is incident on the substrate at angles at or near the Brewster's angle for the given substrate material and the wavelength of the radiation beam, which is linearly P-polarized. The use of a two-dimensional laser diode array allows for a polarized radiation beam of relatively high energy density to be delivered to the substrate, thereby allowing for LTP processing with good uniformity, reasonably short dwell times, and thus reasonably high throughput.

An F2-excimer laser has multiple closely-spaced spectral lines of interest around 157 nm, and one of the lines is selected by wavelength selection optics. The wavelength selection optics of a first preferred embodiment include a birefringent Brewster window enclosing the laser gas volume of the discharge chamber. The window preferably comprises MgF2 and is located at one end of the discharge chamber. One line is selected of the two when the optical thickness of the window is selected in coordination with rotatably adjustable, orthogonal refractive indices of the window. The transmissivity of the window is dependent on the orthogonal refractive indices and the optical thickness of the window. The wavelength selection optics of a second preferred embodiment include are at least partially within the laser active volume. In this way, line selection is performed in a manner which optimizes the combination of optical and discharge efficiency, resonator size and cost. The wavelength selection unit preferably includes a prism having a front surface oriented at Brewster's angle and a back surface oriented to receive and reflect an ordinary refracted ray travelling within the prism at a right angle to the back surface. The back surface also preferably includes a highly reflective coating to serve as the highly reflective surface of the resonator. The wavelength selection unit preferably further comprises an adjustment component for adjusting the orientation of the prism and for enclosing the other end of the housing, opposite the outcoupling end.

A detection system comprises a transmitter unit, a receiver, and a processor. The transmitter unit is capable of transmitting a first collimated beam having a first frequency and a second collimated beam having a second frequency into a ground, wherein the first collimated beam and the second collimated beam overlap in the ground. The receiver is capable of monitoring for a response radio frequency signal having a frequency equal to a difference between the first frequency and the second frequency. The response radio frequency signal is generated by an object having non-linear conductive characteristics in response to receiving the first collimated beam and the second collimated beam. The processor is capable of controlling an operation of the transmitter unit and the receiver. The processor is connected to the transmitter unit and the receiver. The object is detected when the response radio frequency signal is detected by the receiver.

A laser for outputting radial polarized light beam comprises a pumping source, is characterized in: a pumping light shaping and coupling apparatus, a front cavity mirror, a laser medium, a Brewster shaft vertebra mirror and a rear cavity mirror are disposed successively along the direction of the pumping light from the pumping source; the centered wavelength of the pumping light from the pumping source is the same with the absorption wavelength of the laser medium; the pumping light passes through the pumping light shaping and coupling apparatus and is focused onto the laser medium; and the Brewster shaft vertebra mirror is made of high refractive index material, has a drift angle twice of the complementary angle of the Brewster angle. The invention achieves the advantages of simple structure, low cost, good quality of outputted radial polarized light beam.

A non-contact method for determining the index of refraction or dielectric constant of a thin film on a substrate at a desired frequency in the GHz to THz range having a corresponding wavelength larger than the thickness of the thin film (which may be only a few microns). The method comprises impinging the desired-frequency beam in free space upon the thin film on the substrate and measuring the measured phase change and the measured field reflectance from the reflected beam for a plurality of incident angles over a range of angles that includes the Brewster's angle for the thin film. The index of refraction for the thin film is determined by applying Fresnel equations to iteratively calculate a calculated phase change and a calculated field reflectance at each of the plurality of incident angles, and selecting the index of refraction that provides the best mathematical curve fit with both the dataset of measured phase changes and the dataset of measured field reflectances for each incident angle. The dielectric constant for the thin film can be calculated as the index of refraction squared.

The present invention provides a laser beam combining system, comprising a first laser, a second laser, a reflecting mirror, and a beam combining mirror, wherein the beam combining mirror is a thin film polarizer, the beam combining mirror includes a first mirror surface and a second mirror surface, and the first laser outputs A reflector is arranged on the center line of the optical path. After being reflected by the reflector, the laser beam output by the first laser is incident on the first mirror surface of the beam combiner and reflected by the mirror surface. The laser beam emitted by the second laser is at the Brewster angle. Incident to the beam combiner, after the laser beam emitted by the second laser is transmitted through the beam combiner, it overlaps with the laser beam reflected by the first mirror surface of the beam combiner to form a beam. The invention also discloses a laser beam combining method. The laser beam combining system of the present invention can combine laser beams emitted by lasers of the same type. The power of the combined output laser beam is twice that of the single beam laser power, which can meet the requirements of high laser power for processing and use under the premise of ensuring the stable operation of the laser.

A dual-photoelectric Q-switched Nd:YAG laser includes a main optical path on a main oscillation axes composed of an output coupling mirror, a Nd:YAG bar, a polariser, a first 1/4 wave plate, a first Q-switched crystal and a first back control mirror arranged orderly, in which, said polarizer is in Brewster angle with the opposite direction of emitted laser, which is charactered that a Q-switched branch is along the direction of depolarization lost of the polarizer and is composed of a second 1/4 wave plate, a second Q-switched crystal and a second back cavity mirror. This invention adds a Q-switched branch along the depolarization lost output optical path on the basis of the traditional Q-switched polarization cavity, so that, lost component is fed back to the cavity along the original path via the Q-switched switch to form effective laser output.

The invention discloses an imaging method based on polarized light extinction to solve the problems of low imaging definition and lacking of instantaneity when a target object is photographed under saturated light in the prior art. The method includes the steps of controlling an included angle between the connecting line from the object to the paragraphed to a light source and the connecting line from the object to be paragraphed to a camera to be twice as large as the Brewster angle, arranging a polarizing film perpendicular to an optical axis of the camera in front of a lens of the camera, paragraphing a plurality of polarization images with different polarization angles through the rotation of the polarizing film, designating a pixel point window for each polarization image, comparing a grey value of each pixel point in each pixel point window with a threshold value, and selecting pixel points in the pixel point window with the minimum number of pixel points of which the grey values are larger than the threshold value to conduct fusion imaging.

A projection system is disclosed, in which a screen may have improved rejection of ambient light by having a high reflectivity at low angles of incidence for a polarization parallel to that of the projector, a low reflectivity at high angles of incidence for a polarization parallel to that of the projector, and a low reflectivity at both low and high angles of incidence for a polarization perpendicular to that of the projector. In some embodiments, for p-polarized light polarized parallel to the projector, the power reflectivity is high at low angles of incidence and decreases to a low value at high angles of incidence. In some embodiments, for p-polarized light polarized perpendicular to the projector, the power reflectivity is low at low angles of incidence. In some embodiments, for s-polarized light polarized perpendicular to the projector, the power reflectivity remains low at all angles of incidence. In some embodiments, the screen includes a thin film structure that has alternating quarter-wave layers of isotropic and birefringent materials, which are refractive-index-matched for light polarized perpendicular to the projector, which form a high reflector at normal incidence for light polarized parallel to the projector, and which exhibit Brewster's angle effects for p-polarized light polarized parallel to the projector at high angles of incidence. The Brewster's angle effect may be reached by use of a light-scattering layer that increases the effective incident refractive index.

The invention provides a micro-miniature NMR (nuclear magnetic resonance) gyroscope with application of an oblique-incidence detection light path. The micro-miniature NMR gyroscope comprises a dual-window atomic gas chamber prepared with an MEMS (micro-electromechanical system) technology, a heating structure for heating the atomic gas chamber, a magnetic field coil, a detection light path assembly, a pumping light path assembly, a photoelectric detection assembly, a signal demodulation module, a temperature control module, a magnetic field drive module and a laser drive module. According to the NMR gyroscope, the thin-sheet dual-window atomic gas chamber prepared with the MEMS bonding technology is adopted, the pumping light path and the detection light path adopt a circularly polarized light vertical window pumping mode and a linearly polarized light oblique-incidence detection mode respectively, the light path structure of the gyroscope is simplified, the overall size of the gyroscope is reduced, and meanwhile, by means of Brewster angle incidence adopted by linearly polarized detection light, high transmittance and high linear polarization degree of the detection light can be realized.

A conductively cooled high-repetition single frequency Nd: YAG Laser is disclosed. An improved resonance detection method is used to obtain an injection-seeded single frequency pulse laser. A laser resonator is a u-shaped cavity, which uses two high peak power LD to pump a laser crystal from ends. High-precision TEC is used to control the temperature of the laser crystal. With changes of applied voltage on piezoelectric ceramics, seed lights reflected twice from a Brewster angle polarizing sheet interfere with each other. Interference signals received by photodiodes are processed by a sequential control system and when there is a maximum value, Q-witch is opened by the sequential control system. And then a close-to-diffraction-limited single-rate pulse laser is output. According to changes of light extraction time, system can give a negative feedback so that a cavity length can be maintained stably. The invention possesses a high-repetition frequency, high energy, conduction cooling, narrow linewidth, high frequency stability, and a compact structure and can work stably.

A system including a microscope and an inspection apparatus in which an objective lens having a large numerical aperture is used for detecting a defect existing inside a sample. A light source apparatus produces linearly polarized light. The polarization maintaining fibers optically coupled to the light source apparatus project the linearly polarized light onto the sample surface as an illumination beam of P-polarized light at an incidence angle substantially equal to the Brewster's angle of the sample. The scattered light generated by the defect existing in the sample is emitted from the sample and is collected by the objective lens whose optical axis is perpendicular to the sample surface. Since the illumination beam of P-polarized light is projected at the incidence angle equal to the Brewster's angle of the sample, no surface reflection occurs and it is possible to use the objective lens having a large numerical aperture.

The invention discloses a refractive index measuring instrument for transparent material with the Brewster angle, comprising an upright post and a one-fourth circular arc guide rail taking the upright post as the radius. The guide rail is provided with a laser emitter which can slide along the circular arc direction of the guide rail and is opposite to the direction of the center of a circle of the circular arc guide rail, and an objective table is arranged at the center position of the circle of the circular arc guide rail; the upright post is vertically provided with a scale beam below which a polarization film strip is arranged, and a photoelectric sensor is arranged between the polarization film strip and the scale beam and connected with a digital display indicator. The method simplifies a traditional complex refractive index detecting method, can conveniently and simply confirm the components of the transparent material, can accurately measure the refractive index when the three-dimensional surface of the transparent material is not regular without polishing the surface, and can measure the refractive index only by finding a small reflecting surface on a measured object without damaging original ore.

The invention provides a terahertz-wave parametric oscillator based on a cube-corner prism resonant cavity, which is characterized in that the resonant cavity is formed by a right-angle trihedral cube-corner prism and an output mirror; the right-angle trihedral cube-corner prism can rotate around a cavity axis of the resonant cavity; the resonant cavity is internally provided with a MgO: LiNbO3 crystal; a silicon prism array is put on the surface of the MgO: LiNbO3 crystal; and a polarizer is arranged between the right-angle trihedral cube-corner prism and the MgO: LiNbO3 crystal according to a Brewster angle; pumplight is incident to the resonant cavity to simulate the MgO: LiNbO3 crystal to generate terahertz-wave which is sent out by the silicon prism array. Frequency tuning output of terahertz-wave is realized by rotating the output mirror without needing integrally rotating the resonant cavity. The oscillator is a continuously tunable full-solid state terahertz-wave coherent radiation source with small volume, compact structure, and high working stability and can be widely applied to terahertz-wave photoelectronic technique fields such as medical diagnosis, fine spectral analysis, biomedical Imaging, terahertz-wave communication, etc.